package oj;

public class MergeTwoLists {
    public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
        ListNode newHead = new ListNode(-1);
        ListNode tmp = newHead;
        while(list1 != null && list2 != null){
            if(list1.val < list2.val){
                tmp.next = list1;
                list1 = list1.next;
                tmp = tmp.next;
            }else{
                tmp.next = list2;
                list2 = list2.next;
                tmp = tmp.next;
            }
        }
        if(list1 == null){
            tmp.next = list2;
        }
        if (list2 == null){
            tmp.next = list1;
        }
        return newHead.next;
    }
}
